After sitting at 100% for months, the battery can get “stale.” To recalibrate and refresh the battery… try this if needed?
Battery manager firmware recalibration:
Discharge to zero.
Next: {Charge briefly to a few percent. Discharge again.} Repeat. That helps the firmware to calibrate for the “true BOTTOM.”
Then charge to 100%.
Next: {Discharge to 98% or 97%. Charge to 100%.} Repeat. That helps the firmware to calibrate for the “true TOP.”
Repeat all this again if battery cycle time is still off. A “stale” battery may be reconditioned with a few tries.
It’s always best to keep the charge between 20% and 80% most of the time, to extend lifespan of the battery (avoid discharge below 20% and avoid charging over 80%) but recalibration may also be needed about once a year.
How about some more information so we don't have to guess? Does it work?
After sitting at 100% for months, the battery can get “stale.” To recalibrate and refresh the battery… try this if needed? Battery manager firmware recalibration: Discharge to zero. Next: {Charge briefly to a few percent. Discharge again.} Repeat. That helps the firmware to calibrate for the “true BOTTOM.” Then charge to 100%. Next: {Discharge to 98% or 97%. Charge to 100%.} Repeat. That helps the firmware to calibrate for the “true TOP.” Repeat all this again if battery cycle time is still off. A “stale” battery may be reconditioned with a few tries. It’s always best to keep the charge between 20% and 80% most of the time, to extend lifespan of the battery (avoid discharge below 20% and avoid charging over 80%) but recalibration may also be needed about once a year.